This invention relates to a simple apparatus and method for determining the chamber pressure in a firearm. This apparatus and method may be used with any firearm and requires no physical modification of the firearm or cartridge.
It is well known by those who load ammunition that chamber pressures produced by a given combination of cartridge components will differ depending on what firearm the cartridge is fired in. This may be due, for instance, to differences in the size of the chamber, length of the chamber throat and/or barrel dimensions. Furthermore, particularly among those who handload ammunition, it is well known that any change in amount of powder, weight of bullet, lot of primers and/or even the manufacture of cartridge case effect changes in chamber pressure.
Because the pressures produced by a particular load (combination of components) may be dangerous or result in suboptimal performance of a firearm, it is important to have a convenient and inexpensive method of determining the pressure of a particular loading in a given firearm.
One object of this invention is to provide the handloader with an apparatus and method for determining chamber pressure without altering or damaging the firearm or cartridge to be tested.
Another abject of this invention is to provide a simple, efficient and inexpensive means of determining the pressure of a given load without puncturing or otherwise physically altering the cartridge case.
Another objective of the invention is to provide the user with a plastic substance separate from the cartridge case wall and of predetermined size, shape and performance characteristics which make it amenable to the purpose of changing shape under the pressures developed inside chambers of firearms.
Furthermore, an object of this invention is to provide an optimal means of attaching the plastic substance to the cartridge case such that it will remain in place after firing, insure uniform spread of the plastic substance and facilitate measurement of the plastic substance.
Another object of this invention is to provide the user with data and a standard curve relating the width of the plastic substance to pounds per square inch from which the pressure in pounds per square inch can be determined.
These and other objects and advantages will become apparent upon reading the following brief description and studying the accompanying drawings.